While deadbolt locks have in the past adequately secured doors and the like against unauthorized entry, they are now being subjected to unprecedented abuse and assault. Cylinder operated locks have been provided with pick resistant cylinders, but picking the lock is not always the major problem to be guarded against. Rather, the lock mechanism, or more specifically the cylinder, is pried from its setting by a crowbar or similar tool. Escutcheons are often provided to encircle a lock cylinder to prevent a tool being inserted into the door adjacent the periphery of the cylinder and used to pry the cylinder out of the lock. In the absence of an escutcheon, this could be done because the cylinder is held in place by two machine screws which pass through a retaining plate on the opposite side of the door and into the back side of the cylinder, thus holding the cylinder against the front side of the door. When subjected to the force exerted by a crowbar, the screws simply fail in tension thus allowing the cylinder to pop out of the lock. With the cylinder removed, the bolt can easily be withdrawn from engagement with the door jamb.